Vaporizable air-treating materials, such as cardboard, fibreboard, or other fibrous carriers soaked with volatile liquids, provide an effective means for gradual introduction into the air of air-treating vapors, including vapors used for air freshening or the killing of insects. In the packaging of these volatile materials, it is desirable to utilize dispensers which provide adequate retention of the volatiles while effectively controlling the rate of their evaporation and the dispensing of air-treating vapors during use. Other desirable characteristics for dispensers of air-treating vapors are simplicity in construction and operation and attractiveness in appearance.
A wide variety of such dispensers for air-treating vapors have been developed, including the dispensers disclosed in U.S. Pat. Nos. 2,765,950; 2,830,845; and 4,014,501. Such dispensers of the prior art have varying advantages and disadvantages. Some may be difficult to operate, requiring, for example, two hands for adjustment or a period of learning for operation. Some, because of various mechanical requirements, impose design limitations which are harmful to product aesthetics. A need remains for a superior, easily operated air freshener of the type having two principal interengaged portions which are adjustable to different vertically spaced positions with respect to each other to control dispensing.